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APPENDIX IV A- 4 Relationship between Conductivity and Morphology of Ternary Polymer Blends This annex is a comprehensive study of a ternary blend for the case of complete wetting in which conductivity data are used to justify the behavior of a ternary blend, which is attributed to its morphology and is based on the composition of its components. It was observed that the lowest percolation threshold (as low as 3%) for a ternary blend has been found in a double percolated structure for the complete wetting case. Due to high interfacial tension between PANI and common polymers, it is almost impossible to situate PANI at the interface. According to the positive spreading coefficient of PVDF over PANI (λPVDF/PANI = 7.3 mN/m in HDPE/PVDF/PANI) (Figure A-4.1), PVDF is forced to the interface. In this case, PANI and HDPE situate in the inside and outside, and PVDF locates at the interface. The lower interfacial tension between PVDF and PANI results in the interpenetration of the entire PANI and PVDF in each other, and the formation of small phase sizes. Some big parts of PVDF polymer have been clearly removed after extraction of PVDF by DMF in such a morphology (Figure A-4.1a). Solvent extraction/gravimetric measurement reveals that some part of the PANI entrapped in the PVDF phase is removed with PVDF. By decreasing the amount of PVDF to as little as 20%, as shown in Figure A-4.1b, the number of large PVDF islands reduces. These disappearances of large PVDF parts continue with the reduction of the amount of PVDF until no large PVDF parts are observed in the 45/10/45 HDPE/PVDF/PANI blend (Figure A-4.1c). However, the large parts of PVDF play an important role in reducing the percolation threshold of PANI, as they occupy some spaces in the blend and limit the presence of PANI in those areas. It can be concluded that one of the best ways of reducing the percolation threshold, despite the doublepercolated structure, is occupying places with other components. In a 33/33/33 HDPE/PVDF/PANI blend, the area occupied by PANI has been limited because of continuous phases of PVDF and HDPE, and large PVDF areas. This results in a lower percolation threshold 252
of PANI, and an increase in the conductivity of the sample, as for this blend conductivity reaches a relatively high value of 0.017 S/cm. a) b) c) Figure A-4.1. Scanning electron micrographs of HDPE/PVDF/PANI after extraction of PVDF by DMF (a) 33/33/33, (b) 40/20/40, and (c) 45/10/45 The approach obtained for HDPE/PVDF/PANI can be used to decrease the percolation threshold of PANI in a HDPE/PEMA/PANI blend. In such a conversion, HDPE plays a major role as it forms a continuous structure containing large rods and branches, and consequently limiting the space, whereas PANI can generate clusters only in limited routes. In this part, two ternary blends of HDPE/PEMA/PANI and PS/PEMA/PANI are studied from electrical and morphological points of view. It is shown that the high surface tension of HDPE and PANI results in a positive spreading coefficient: λPEMA/PANI = 8 mN/m in HDPE/PEMA/PANI, according to the Harkins equation (interfacial tensions are listed in Table A-4.1). Therefore, PEMA locates at the interface of HDPE and PANI, separating them. In such a morphology, due to high interfacial tension between HDPE and PEMA, large continuous parts of HDPE exist in the blend, which restricts the area for diffusion of PANI. Therefore, connected pathways of PANI are achieved at a lower amount of PANI, leading to a decrease in the percolation threshold of PANI, and subsequently increasing the value of conductivity. In the ternary PS/PEMA/PANI, due to a positive spreading coefficient of λPEMA/PANI = 3.2 mN/m, the PEMA phase is located at the interface of the PS and PANI phases (Table A-4.1). Contrary to the previous case, with a low amount of PANI, the percolation threshold is not reached due to the low interfacial tension of PS and PEMA, resulting in PANI droplets remaining in the blend. 253
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© Sepehr Ravati, 2010. UNIVERSITÉ
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DEDICATED To my parents iii
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RÉSUMÉ Cette thèse présente, po
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devenir une structure hiérarchique
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ABSTRACT This thesis presents, for
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system can be increased from 10 -15
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CONDENSÉ EN FRANÇAIS Dans ce trav
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deuxième coquille de PS. Les phase
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structures à percolation multiple
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autre sous-type de morphologie dans
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TABLE OF CONTENTS DEDICATION.......
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xxiii 2.4.1.1.1 Charged Polymer Ads
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5.3.4 Annealing Test ..............
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xxvii REFERENCES ..................
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LIST OF FIGURES xxix Figure 1-1. a)
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Figure 2-12. SEM photomicrograph of
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Figure 2-34. Schematic view of diff
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Figure 4-8. SEM micrographs of vari
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Figure 5-6. a),b) Scanning electron
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and c) triangular concentration dia
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n number of moles p concentration o
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AFM atomic force microscopy LIST OF
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PS-co-PMMA copolymer of PS and PMMA
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1.1 Introduction CHAPTER 1 - INTROD
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Figure 1-2. Human heart, longitudin
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One of the applications for porous
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On the other hand, a novel tri-cont
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2.1 Polymer Blends CHAPTER 2 - LITE
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Based on Sterling’s approximation
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Antonoff’s rule (Equation 2-13) i
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2.1.2.1 Binary Polymer Blends 2.1.2
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Some other studies(Everaert, Aerts,
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where the parameter z is dependent
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“compatibilization” was suggest
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a) λ BC A and B are matrices, b) C
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Reignier & Favis, 2000, 2003a; Reig
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measure the interfacial tension of
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a) b) Figure 2-6. Dependence of the
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Omonov et al. found double percolat
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2.1.2.2.3 Effect of Composition on
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a) b) C B A c) Figure 2-12. SEM pho
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In the case where PS is the matrix,
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Posthuma de Boer, 1999) (Kumin & Ch
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lattice, such as square lattice, wi
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magnetization, which is a function
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Polymers have long been thought of
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epoxy as a function of nanotube wei
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Figure 2-19. Approaching the percol
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Figure 2-21. Transmission electron
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Figure 2-22: Dependence of PE conti
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Figure 2-24. Plot of the total numb
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chain provides the conductive path
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2.3.1.2.1 Polyaniline One of the mo
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CoPA/LLDPE/PANI blend and a poor-qu
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Narkis and co-workers extended and
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Figure 2-31: Conductivity of PVDF/P
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organic thin films, a novel and str
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on the topic have been reported in
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succeeded in creating thin films wi
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Addition of salt to the solution of
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different from that of linear homop
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Figure 2-39. Macromolecule with a)
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polyanion such as hyaluronan (HA)(P
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2.4.1.1.7 Effect of Salt on Multila
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2.4.1.1.8 Overcompensation of the M
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important factors determining the g
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As shown in Figure 2-44, swelling a
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increasing the pH value due to a de
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CHAPTER 3 - ORGANIZATION OF THE ART
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discussed above, HDPE, PS, PMMA, an
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CHAPTER 4 - LOW PERCOLATION THRESHO
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or model which predicts where the p
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concentration threshold for the ons
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chemical and weathering resistance,
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Table 4-1. Material Characteristics
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filled with blend pellets. To facil
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4.3.6 Conductivity Measurements DC
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experimentally in this research gro
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a) b) c) d) Figure 4-4. Schematic i
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microstructure of the quaternary bl
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a) b) c) d) Figure 4-6. SEM microgr
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a) b) PVDF PS PMMA c) d) e) HDPE PS
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Uniform layers of PS and PMMA situa
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the concentration of HDPE is increa
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a) b) c) e) Figure 4-11. SEM microg
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melt-processable and contains 25 wt
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One question that should be address
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Conductivity(S/cm) Ternary Blend 1,
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phase(PMMA), the concentration of P
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(6) Virgilio, N.; Desjardins, P.; L
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ONION MORPHOLOGY HDPE PVDF PS Contr
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work described above has focused on
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thermodynamic explanation to predic
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four-point probe increases continuo
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in the rheology tests were compress
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5.3.6 Layer-by-Layer Deposition The
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prepare a polymer blend structure w
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a) b) c) Figure 5-3. Scanning elect
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spontaneously self-assembled. After
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a) b) c) d) e) f) g) h) Figure 5-5.
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Since the ultra-low surface area va
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c) a) b) Figure 5-6. a),b) Scanning
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salt to a PSS polyelectrolyte solut
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A relationship between macropore si
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close together. It is interesting t
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Figure 5-9. Mass increase (%) indic
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In this work the conductance of the
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deposited PANI layers increases unt
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(52) Guo, H. F.; Packirisamy, S.; G
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6.2 Introduction It is well-known t
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modified version of Harkins theory(
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6.3 Experimental 6.3.1 Materials Co
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Complex voscosity (Pa.s) 1,0E+04 1,
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6.3.5.2 Focused Ion Beam (FIB) and
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a) c) b) d) e) f) PMMA PMMA HDPE HD
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y Harkins theory, PS will always si
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a) b) c) d) e) f) PS Figure 6-6. a)
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a) b) HDPE : black PS : grey PMMA :
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6.4.6 Continuity, Co-continuity, an
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c) V III II I VII I IV VI Figure 6-
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Continuity Scheme (a) Figure 6-10.
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Addition of a low concentration of
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Addition of small amounts of HDPE t
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Page 249 and 250: Three examples are shown in Figure
Page 251 and 252: (9) Mekhilef, N.; Verhoogt, H. Poly
Page 253 and 254: structures are formed due to the co
Page 255 and 256: CONCLUSION AND RECOMMENDATIONS In t
Page 257 and 258: REFERENCES A. K. Gupta, K. R. S. (1
Page 259 and 260: Caruso, F. (2003). Hollow Inorganic
Page 261 and 262: Domenech, S. C., Bortoluzzi, J. H.,
Page 263 and 264: Geuskens, G., Gielens, J. L., Geshe
Page 265 and 266: Hou, S., Harrell, C. C., Trofin, L.
Page 267 and 268: Krass, H., Papastavrou, G., & Kurth
Page 269 and 270: Macdiarmid, A. G., Jin-Chih, C., Ha
Page 271 and 272: Niziol, J., & Laska, J. (1999). Con
Page 273 and 274: Reghu, M., Yoon, C. O., Yang, C. Y.
Page 275 and 276: Shirakawa, H., Louis, E. L., MacDia
Page 277 and 278: Utracki, L. A. (1991). On the visco
Page 279 and 280: Yasuda, K., Armstrong, R., & Cohen,
Page 281 and 282: literature has examined factors inf
Page 283 and 284: (Reignier & Favis, 2000, 2003a; Rei
Page 285 and 286: Table A-1.2. Interfacial tensions a
Page 287 and 288: acquisition of images with a very h
Page 289 and 290: Table A-1.3. Continuity of the PMMA
Page 291 and 292: (17) Reignier, J.; Favis, B. D., Ma
Page 293 and 294: PANI. Theoretically, the extent of
Page 295 and 296: Equation A-2.7 0( ) 0 1. 5 σ = σ
Page 297: Cumulative Mass × 10 5 (g) dipping
Page 301 and 302: Resistance(ohm) 1.0E+12 1.0E+11 1.0
Page 303 and 304: esistance value. Samples containing
Page 305 and 306: The results of resistance for PS/PE
Page 307 and 308: Caruso, F., & Schuler, C. (2000). E
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